Combine cornmeal mix, scallions, jalapeno, garlic, salt and pepper in a bowl.
Whisk together beer, buttermilk, and egg; stir into cornmeal mixture and set aside.
Heat oil in a 10 inch skillet until it shimmers.
Dredge fish nuggets in fish fry mix then fry on only one side, in hot oil, 2 minutes.
Pour hush puppy batter over fish in skillet. Transfer skillet to oven and bake until hush puppy is golden and a toothpick inserted in the center comes out clean, 15 minutes. Let meal rest 5 minutes, then loosen edges with a knife. Top skillet with a serving plate and flip.
Whisk ketchup, mayonnaise, relish and horseradish in a bowl.